1. Field of the Invention
The present invention relates to thermally responsive sealing assemblies, and more particularly to a temperature responsive sealing assembly for effecting a fluid tight seal between fluid containing members, the assembly including thin nested actuators, each having a unique coefficient of thermal contraction and possessing a cam surface positioned for camming engagement with a corresponding cam surface on a neighboring actuator for altering the overall physical dimensions of the assembly in response to temperature changes.
2. Description of the Related Art
In the past, a variety of seals capable of functioning effectively at ambient temperatures, as temperatures above ambient temperature, were well-known.
However, finding a seal which functioned below, as well as at, ambient temperature posed a major problem due to the fact that materials of which resilient seals could be composed had characteristics that were detrimental to the sealing efficiency as the temperature decreased.
For example, the shrinking of a sealing ring caused by exposure to extreme cold temperatures, as encountered in cryogenic applications where the temperatures range well below -200.degree. F. created a tendency for the sealing ring to pull away from the walls of the members between which the ring was disposed, unless the sealing ring was preloaded into sealing engagement with sufficient force to resist the inherent shrinkage. However, such preloading was detrimental to the sealing ring when operating at ambient temperature or subambient temperature.